A Closed Infrared Detector Cooling System

Abstract

The successful operation of the present types of infrared detection systems depends primarily on the response and sensitivity of the most vital part of the system, namely, the detector sensing element. Many of these elements, in turn, require cooling to temperatures in the vicinity of 75 to 100°K in order to detect present-day targets traveling at high speeds. One of the major problems in the development of these infrared systems has been to provide adequate cooling in a reliable manner either over short or long periods of time with a minimum of cryogenic hardware. The reliability factor and me logistic field requirements have been only approximately met by the majority of present-day, open-type cooling systems. Moreover, for those systems that require long periods of operation in flight, there is frequently a significant weight advantage in favor of closed-system refrigeration. Thus, there exists a definite need for a closed infrared detector cooling system. The latter is the subject of this paper.